Growing plants indoors can be a rewarding hobby or even a way to produce your own fresh herbs, vegetables, and flowers year-round. However, indoor plants have different lighting requirements than plants grown outdoors. Choosing the right type of indoor lighting is essential for healthy plant growth. The three main options for growing lights are fluorescent, LED, and high-intensity discharge (HID) lights. Each has its own advantages and disadvantages in terms of energy efficiency, cost, heat output, and suitability for different types of plants. This article will compare the different types of grow lights and provide recommendations on which lighting is best for common household and indoor garden plants.
Comparing Major Types of Grow Lights
Fluorescent lights were once the most common type of indoor growing light. Fluorescent tubes come in a variety of color temperatures, from warm (redder light) to cool (bluer light). Cool white fluorescent lights around 5000-7000K are generally recommended for plant growth, since they contain more of the blue wavelength that mimics natural sunlight. Here are some key factors to consider with fluorescent growing lights:
- Low energy use – Fluorescents are energy efficient and don’t generate much heat.
- Low cost – Fluorescent fixtures are inexpensive to buy.
- Compact size – Fluorescent tubes come in small sizes for confined spaces.
- Limited intensity – Fluorescents may not provide enough light for flowering or fruiting plants.
- Light spectrum – Some fluorescents lack red spectrum that plants need for flowering/fruiting.
LED growing lights use lightweight, energy-efficient LED diodes to produce color light in precise wavelengths. Full-spectrum LED grow lights provide a balance of warm red and cool blue light. LED lights generate much less heat than other types. Benefits of LED grow lights include:
- Energy efficiency – LEDs use up to 85% less energy than incandescent lighting.
- Long lifespan – LEDs can last 50,000 hours or more before burning out.
- Compact size – Small LED arrays take up little space.
- Focused intensity – LEDs allow precise direction of high intensity light.
- Low heat – LEDs won’t burn delicate plants.
- Light spectrum – Tunable to specific plant needs.
High Intensity Discharge (HID) Lights
HID grow lights include metal halide and high-pressure sodium fixtures. They produce an intense wide-spectrum light that works well for fruiting and flowering plants. However, they also consume significant electricity and generate a lot of heat. Benefits and drawbacks include:
- Very bright – HID lights allow compact growth and high yields.
- Full spectrum – Metal halides offer a complete spectral range.
- High electricity use – HID lights are the least energy efficient option.
- Substantial heat – HID lights require proper cooling systems.
- High upfront cost – HID light kits can be expensive.
Grow Light Recommendations by Plant Type
Certain plants have particular light requirements to thrive indoors. Here are some general guidelines for choosing grow lights tailored to specific plants:
|Plant Type||Recommended Grow Lights|
|Leafy greens, herbs||Fluorescent, LED|
|Flowering plants||Full spectrum LED, Metal halide HID|
|Fruiting plants||High pressure sodium HID, Switchable LEDs|
|Seedlings, clones||Compact fluorescents, low wattage LEDs|
|Succulents, cacti||LED, high sunlight exposure|
Leafy Greens and Herbs
Lettuce, kale, spinach, basil, and other leafy plants grow well under fluorescent or LED lights. They require lower light intensity but still appreciate full spectrum light. Cool white fluorescent tubes complemented by warmer red fluorescent or LEDs work well. Position lamps 6-12 inches above plants. Lettuces need about 10-14 hours of light per day from seed to mature plant.
Blooming ornamentals like orchids, African violets, and bromeliads thrive under HID or full-spectrum LED lights. Flowering plants need 12-16 hours of bright light daily, and LEDs can provide intense light without excessive heat. HID lights also drive vigorous flowering but require proper temperature control. Position lights 12-24 inches above flowering plants.
Tomatoes, peppers, and other fruiting vegetables require intense light from HID or high-wattage LED lamps. Switchable LED arrays allow adjusting the red/blue spectrum for optimal fruiting. High pressure sodium HID lights also satisfy fruiting plants’ light hunger. Maintain 14-18 hours daily of direct HID or LED illumination about 18-36 inches from foliage.
Seedlings and Clones
Young seedlings and plant cuttings need gentle, lower intensity light. Compact fluorescents or low wattage LED panels give developing plants plenty of light without overheating them. Position lamps 4-8 inches above seedlings for 14-16 hours of light per day. Gradually increase intensity as plants mature.
Succulents and Cacti
Succulents and cacti thrive on bright sunlight. LED grow lights best mimic the sun’s rays at an intensity the plants enjoy. Mixing warmer red and cool blue LEDs sustains healthy growth. Provide 14-18 hours of daily light about 8-15 inches above succulents. Minimizing water keeps these drought-tolerant plants happy.
Additional Grow Light Selection Considerations
Along with matching lights to specific plant types, there are other factors that determine the best grow lights for an indoor garden setup. Assess the following elements when choosing fixtures:
- Available space – Size and shape of grow area impacts spacing and positioning of lights.
- Height adjustment – Ability to raise/lower lights as plants grow.
- Automated controls – Timers or automated systems to regulate photoperiods.
- Number of plants – More plants require more or higher intensity lights.
- Budget – Initial equipment outlay plus ongoing electricity costs.
- Heat management – Proper ventilation and cooling for heat from lights.
Also factor in safety issues like preventing electrical hazards and fire risks. Position hot HID lights an adequate distance from flammable surfaces. Consider connectinggrow lights to grounded timers for automatic photoperiod regulation based on plant needs.
Sample Indoor Garden Setup with Grow Lights
An example indoor gardening scenario could involve a 4′ x 2′ space for nurturing leafy greens and flowering annuals. Quality full-spectrum LED panels offer energy efficiency and modest heat generation. Here is a hypothetical small indoor garden setup:
- Metal shelving standing 7 feet tall to accommodate two planting levels
- LED grow light panels hung from chains on ceiling at adjustable heights
- Top shelf for starting seeds and cuttings under fluorescent light
- Middle and lower shelves for lettuces under LED lights
- Timing system on LED lamps for 16 hours daily on, 8 hours off
- Clip-on circulating fans for airflow and cooling as needed
This type of configuration allows adequate intensity for the selected plants without excessive energy use or complicated cooling needs. The adjustable LED lights can be kept close to the young plants and raised as they mature.
Choosing the correct grow lights makes all the difference in successfully growing thriving plants indoors. Determine lighting needs based on the particular crops you want to cultivate. Leafy greens and seedlings flourish under fluorescent or LED lights. Flowering species favor full spectrum LED fixtures or metal halide HID lamps. Fruiting plants demand high intensity discharge or high-power LEDs for vigorous growth. Also factor in the physical layout, automation, and your budget when selecting equipment. With the right lighting in place, you can enjoy raising a vibrant indoor garden any time of year.